US5289140A - Consistent diagnostic test method using microwaves - Google Patents

Consistent diagnostic test method using microwaves Download PDF

Info

Publication number
US5289140A
US5289140A US07/745,688 US74568891A US5289140A US 5289140 A US5289140 A US 5289140A US 74568891 A US74568891 A US 74568891A US 5289140 A US5289140 A US 5289140A
Authority
US
United States
Prior art keywords
microwave
cavity
sample
energizing
slide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US07/745,688
Inventor
Finn Jorgenson
Bent B. Vaboe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dako North America Inc
Original Assignee
Dako Japan Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dako Japan Co Ltd filed Critical Dako Japan Co Ltd
Priority to US07/745,688 priority Critical patent/US5289140A/en
Assigned to DAKO JAPAN CO LTD. reassignment DAKO JAPAN CO LTD. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: JORGENSEN, FINN, VABOE, BENT BORS
Application granted granted Critical
Publication of US5289140A publication Critical patent/US5289140A/en
Assigned to DAKO CORPORATION reassignment DAKO CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DAKO JAPAN CO., LTD.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/80—Apparatus for specific applications
    • H05B6/806—Apparatus for specific applications for laboratory use
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N22/00—Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/5306—Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/70—Feed lines
    • H05B6/705—Feed lines using microwave tuning

Definitions

  • microwaves can be used for increasing chemical reaction rates and thereby shortening the time needed for reaching reaction equilibria. This fact is of importance in connection with diagnostic test procedures, and microwave ovens are already in use for reducing the time required for certain diagnostic tests, especially when it is essential to obtain the test results as fast as possible, e.g. in connection with surgical operations.
  • Microwave ovens are also in common use for food preparation in professional and private kitchens, and present here also the drawback associated with uneven effects from the center of the oven towards the boundaries.
  • the test procedure comprises several process steps, including pretreatment of the specimen e.g. with alcohol or acetone often followed by an enzymatic pretreatment with a proteolytic enzyme; the specimen is then subjected to a solution containing a specific antibody, which will react by coupling to the corresponding antigenic sites on the specimen; secondary antibodies carrying visualization agents may then be added to react with the primary antibody molecules tied to the antigens.
  • the visualization agents may be a radioactive label, a fluorescent compound or an enzyme, which in a subsequent process step may give rise to a color reaction with other reagents added.
  • the total time required for carrying out a test is usually in the range of 30 minutes to several hours, depending on the test system used; some test systems are developed especially for short reaction times by using high concentration of reagents and by other means, thereby reducing reaction times to the range of typically 15-30 minutes.
  • the total reaction time for the above procedures may be reduced by exposing the specimen to microwave radiation during some or all of the process steps included in the test.
  • microwave techniques are thus in principle very simple and requires no special skills other than the skills required for performing a standard diagnostic test without the use of microwaves. Given the considerable interest in shortening the time required for analysis it is therefore surprising that the technique has failed to gain acceptance for general use.
  • the equipment--microwave ovens--used today for applying microwave radiation to test specimens in connection with diagnostic procedures gennerally have the serious drawback of giving a very uneven radiation intensity throughout the radiation chamber.
  • the purpose of using microwave radiation is to reduce the reaction time required, but if radiation intensity is insufficient the chemical reaction will not proceed to the desired extent in the shortened time allotted to each process step; and if the radiation intensity is uneven in the area where the specimens are placed there will be a great uncertainty as to the extend to which the reaction has taken place, and thus an extra uncertainty is imposed on the test results.
  • the radiation intensity can be evened out throughout a large part of the radiation chamber by modifying the source of radiation compared to the presently used microwave equipment.
  • the present microwave equipment available on the market is to our knowledge limited to equipment having a microwave source emitting microwaves of a wavelength corresponding to the dimensions of the radiation chamber. As the result a standing wave is established, with its intensity being at maximum right in the middle of the chamber and declining towards the walls, where the intensity will be zero.
  • FIG. 1 A first figure.
  • the present invention comprises an improved microwave equipment, in which the microwave source emits waves of more than one wavelength.
  • the microwave source or sources emits waves of two different wave lengths. Thereby a certain equilization of radiation intensity is obtained with a rather simple and inexpensive radiation source.
  • the microwave source comprises two separate microwave sources, which in some cases may be more economical than having them combined.
  • the two sources are controllable individually, whereby it becomes possible to further equalize the distribution of radiation intensity throughout the chamber by adjusting the intensity of each microwave of different wavelength in an optimal way.
  • the microwave source or sources emits waves with a distinct number of wavelengths, e.g. three or four corresponding wavelengths. Thereby the pattern of wave intensity throughout the radiation chamber may be optimized.
  • the microwave source comprises two or more separate microwave sources, which in some cases may be more economical than having them combined.
  • the individual sources are controllable individually, whereby it becomes possible to further equalize the distribution of radiation intensity throughout the chamber by adjusting the intensity of each microwave of different wavelength in an optimal way.
  • a further preferred embodiment of the invention comprise a microwave equipment, in which the microwave source emits waves with a broad spectrum of wavelengths, e.g. in the form of "white noise".
  • the microwave source emits waves with a broad spectrum of wavelengths, e.g. in the form of "white noise".
  • a further preferred embodiment of the invention comprise a microwave equipment, in which the microwave source emits square waves with a spectrum of wavelengths including the 1st, 3rd, 5th etc. harmonics.
  • the microwave equipment according to the above may preferably be built into suitable enclosures to eliminate radio frequency interference; said enclosures may further include other known features to make the equipment easy to use for routine purposes both in professional environment such as in the clinical laboratory and in private use e.g. for food preparation in professional or private kitchens.

Abstract

Use of microwave equipment for fast food preparation and for speeding up chemical reactions e.g. in diagnostic testing is wellknown. However in all such uses the known equipment provides a very uneven heating effect, thereby limiting the value of the method. The present patent application describes an improved type of microwave equipment, in which an even effect is obtained by the use of a combination of microwaves of different wavelengths. The equipment according to the invention includes one or more microwave sources, controlled individually or jointly, emitting microwaves of a two or more wavelengths, e.g. in the form of distinct single wavelengths, White Noise, Square Waves.

Description

It is well-known that microwaves can be used for increasing chemical reaction rates and thereby shortening the time needed for reaching reaction equilibria. This fact is of importance in connection with diagnostic test procedures, and microwave ovens are already in use for reducing the time required for certain diagnostic tests, especially when it is essential to obtain the test results as fast as possible, e.g. in connection with surgical operations.
Microwave ovens are also in common use for food preparation in professional and private kitchens, and present here also the drawback associated with uneven effects from the center of the oven towards the boundaries.
In immunohistochemical test procedures the specimen to be tested is placed on a thin glass slide on which all the test reactions take place. The test procedure comprises several process steps, including pretreatment of the specimen e.g. with alcohol or acetone often followed by an enzymatic pretreatment with a proteolytic enzyme; the specimen is then subjected to a solution containing a specific antibody, which will react by coupling to the corresponding antigenic sites on the specimen; secondary antibodies carrying visualization agents may then be added to react with the primary antibody molecules tied to the antigens. The visualization agents may be a radioactive label, a fluorescent compound or an enzyme, which in a subsequent process step may give rise to a color reaction with other reagents added.
To achieve the desired results a strict protocol must be followed when performing the test allowing a certain specified reaction time for each of the process steps involved. The total time required for carrying out a test is usually in the range of 30 minutes to several hours, depending on the test system used; some test systems are developed especially for short reaction times by using high concentration of reagents and by other means, thereby reducing reaction times to the range of typically 15-30 minutes.
It is well-known that the total reaction time for the above procedures may be reduced by exposing the specimen to microwave radiation during some or all of the process steps included in the test.
When using the microwave technique for diagnostic test procedures a special protocol specifying the exact reaction times etc must be followed for each particular test. The procedure to be followed is very similar to the procedure used without microwaves, except that for some process steps the microscopy glass slide containing the specimen and the relevant reagents is placed in the microwave chamber or microwave oven for the specified time periods, usually a few minutes.
The use of microwave techniques is thus in principle very simple and requires no special skills other than the skills required for performing a standard diagnostic test without the use of microwaves. Given the considerable interest in shortening the time required for analysis it is therefore surprising that the technique has failed to gain acceptance for general use.
The equipment--microwave ovens--used today for applying microwave radiation to test specimens in connection with diagnostic procedures, gennerally have the serious drawback of giving a very uneven radiation intensity throughout the radiation chamber. The purpose of using microwave radiation is to reduce the reaction time required, but if radiation intensity is insufficient the chemical reaction will not proceed to the desired extent in the shortened time allotted to each process step; and if the radiation intensity is uneven in the area where the specimens are placed there will be a great uncertainty as to the extend to which the reaction has taken place, and thus an extra uncertainty is imposed on the test results.
Previous attempts to equalize the radiation intensity throughout the microwave radiation chamber include the introduction of a rotating table within the chamber, on which the specimens are placed during their exposure to radiation. This method however still fails to assure a satisfactory consistency in test results and its application makes the equipment unnecesarily complicated mechanically, especially as a high rotation speed seems to be necessary for obtaining any equilization effect with exposure times of only a few minutes.
It has now surprisingly been found that a very substantial evening out of the radiation intensity can be obtained without the use of mechanical means. According to the present invention the radiation intensity can be evened out throughout a large part of the radiation chamber by modifying the source of radiation compared to the presently used microwave equipment.
The present microwave equipment available on the market is to our knowledge limited to equipment having a microwave source emitting microwaves of a wavelength corresponding to the dimensions of the radiation chamber. As the result a standing wave is established, with its intensity being at maximum right in the middle of the chamber and declining towards the walls, where the intensity will be zero.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
The present invention comprises an improved microwave equipment, in which the microwave source emits waves of more than one wavelength.
FIGS. 2-3
Thereby the distribution of microwave intensity will be much improved, because the waves of different wavelength will have their maximum intensities at different locations in the radiation chamber.
In a preferred embodiment of the invention the microwave source or sources emits waves of two different wave lengths. Thereby a certain equilization of radiation intensity is obtained with a rather simple and inexpensive radiation source.
In a preferred embodiment of the invention the microwave source comprises two separate microwave sources, which in some cases may may be more economical than having them combined. Preferably the two sources are controllable individually, whereby it becomes possible to further equalize the distribution of radiation intensity throughout the chamber by adjusting the intensity of each microwave of different wavelength in an optimal way.
In a further preferred embodiment of the invention the microwave source or sources emits waves with a distinct number of wavelengths, e.g. three or four corresponding wavelengths. Thereby the pattern of wave intensity throughout the radiation chamber may be optimized.
In a preferred embodiment of the invention the microwave source comprises two or more separate microwave sources, which in some cases may be more economical than having them combined. Preferably the individual sources are controllable individually, whereby it becomes possible to further equalize the distribution of radiation intensity throughout the chamber by adjusting the intensity of each microwave of different wavelength in an optimal way.
A further preferred embodiment of the invention comprise a microwave equipment, in which the microwave source emits waves with a broad spectrum of wavelengths, e.g. in the form of "white noise". Thereby the desired equalization of radiation intensity is obtained with a single, economical wave source.
A further preferred embodiment of the invention comprise a microwave equipment, in which the microwave source emits square waves with a spectrum of wavelengths including the 1st, 3rd, 5th etc. harmonics.
The microwave equipment according to the above may preferably be built into suitable enclosures to eliminate radio frequency interference; said enclosures may further include other known features to make the equipment easy to use for routine purposes both in professional environment such as in the clinical laboratory and in private use e.g. for food preparation in professional or private kitchens.

Claims (15)

We claim:
1. A method for immunohistochemical testing comprising the steps of:
placing a sample to be tested on a sample slide;
treating the sample;
placing the sample and slide in a microwave cavity;
uniformly energizing the microwave cavity using microwave energy source means including at least three different wavelengths; and
energizing the cavity for a predetermined specified reaction time,
whereby samples are energized consistently with the proper level of microwave energy despite the variations in heating normally found in microwave heating cavities.
2. A method as defined in claim 1, wherein said step of uniformly energizing the microwave cavity includes the application of microwave energy from a substantially square wave source.
3. A method as defined in claim 1, wherein said step of uniformly energizing the microwave cavity includes the application of microwave energy from a substantially white noise source.
4. A method as defined in claim 1, including the additional step of removing the slide from the microwave cavity to review the visualization agents resulting from the process steps.
5. A method as defined in claim 1, wherein said step of uniformly energizing the microwave cavity includes applying the microwave energy to the cavity through a single radiating means coupled to the cavity.
6. A method for immunohistochemical testing comprising the steps of:
placing a sample to be tested in a sample slide;
treating the sample;
placing the sample and slide on a small shelf in a microwave cavity;
uniformly energizing the microwave cavity using microwave energy source means including at least three different wavelengths; and
energizing the cavity for a predetermined specified reaction time,
whereby samples are energized consistently with the proper level of microwave energy despite the variations in heating normally encountered throughout microwave heating cavities.
7. A method as defined in claim 6, wherein said step of uniformly energizing the microwave cavity includes the application of microwave energy from a substantially square wave source.
8. A method as defined in claim 6, wherein said step of uniformly energizing the microwave cavity includes the application of microwave energy from a substantially white noise source.
9. A method as defined in claim 6, including the additional step of removing the slide from the microwave cavity to review the visualization agents resulting from the process steps.
10. A method as defined in claim 6, wherein said step of uniformly energizing the microwave cavity includes applying the microwave energy to the cavity through a single radiating means coupled to the cavity.
11. A method as defined in claim 6, wherein the method includes the step of placing the sample on a microscopy glass slide.
12. Improved microwave equipment comprising:
a microwave source emitting waves of more than one frequency; and
means for supporting an immunohistochemical sample for uniform irradiation by said source.
13. Microwave equipment as defined in claim 12, further comprising a microwave cavity coupled to said microwave source.
14. Microwave equipment as defined in claim 13, wherein said microwave cavity is provided with a door, and a small internal shelf is provided behind said door.
15. Microwave equipment as defined in claim 14, wherein a glass slide carrying said sample is mounted on said shelf.
US07/745,688 1991-08-16 1991-08-16 Consistent diagnostic test method using microwaves Expired - Lifetime US5289140A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US07/745,688 US5289140A (en) 1991-08-16 1991-08-16 Consistent diagnostic test method using microwaves

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US07/745,688 US5289140A (en) 1991-08-16 1991-08-16 Consistent diagnostic test method using microwaves

Publications (1)

Publication Number Publication Date
US5289140A true US5289140A (en) 1994-02-22

Family

ID=24997812

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/745,688 Expired - Lifetime US5289140A (en) 1991-08-16 1991-08-16 Consistent diagnostic test method using microwaves

Country Status (1)

Country Link
US (1) US5289140A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6571648B2 (en) * 2001-03-22 2003-06-03 Kansas Department Of Transportation Method of accelerated aging of neat asphalt binder using microwave radiation process
US6586713B2 (en) 1997-08-20 2003-07-01 The University Of Miami Apparatus for high quality, continuous throughput, tissue fixation-dehydration-fat removal-impregnation
US6793890B2 (en) 1997-08-20 2004-09-21 The University Of Miami Rapid tissue processor
US20050090017A1 (en) * 2003-10-24 2005-04-28 Morales Azorides R. Simplified tissue processing
US20090298172A1 (en) * 2008-05-28 2009-12-03 Steven Paul Wheeler Histological specimen treatment apparatus and method
WO2012003827A3 (en) * 2009-12-16 2012-08-02 Dako Denmark A/S Non-modal interplate microwave heating system and method of heating
US10365189B2 (en) 2015-05-07 2019-07-30 Steven Wheeler Histological specimen treatment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895828A (en) * 1958-02-06 1959-07-21 Gen Electric Electronic heating methods and apparatus
US3867607A (en) * 1972-12-13 1975-02-18 New Nippon Electric Co Hybrid microwave heating apparatus
US4314128A (en) * 1980-01-28 1982-02-02 Photowatt International, Inc. Silicon growth technique and apparatus using controlled microwave heating

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895828A (en) * 1958-02-06 1959-07-21 Gen Electric Electronic heating methods and apparatus
US3867607A (en) * 1972-12-13 1975-02-18 New Nippon Electric Co Hybrid microwave heating apparatus
US4314128A (en) * 1980-01-28 1982-02-02 Photowatt International, Inc. Silicon growth technique and apparatus using controlled microwave heating

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7547538B2 (en) 1997-08-20 2009-06-16 The University Of Miami High quality, continuous throughput, tissue processing
US6586713B2 (en) 1997-08-20 2003-07-01 The University Of Miami Apparatus for high quality, continuous throughput, tissue fixation-dehydration-fat removal-impregnation
US20040004075A1 (en) * 1997-08-20 2004-01-08 The University Of Miami, Harold Essenfeld High quality, continuous throughput, tissue processing
US6793890B2 (en) 1997-08-20 2004-09-21 The University Of Miami Rapid tissue processor
US20080153127A1 (en) * 1997-08-20 2008-06-26 University Of Miami High quality, continuous throughput, tissue processing
US8221996B2 (en) 1997-08-20 2012-07-17 The University Of Miami High quality, continuous throughput, tissue processing
US6571648B2 (en) * 2001-03-22 2003-06-03 Kansas Department Of Transportation Method of accelerated aging of neat asphalt binder using microwave radiation process
US20050090017A1 (en) * 2003-10-24 2005-04-28 Morales Azorides R. Simplified tissue processing
US20090136992A1 (en) * 2003-10-24 2009-05-28 The University Of Miami Simplified tissue processing
US7470401B2 (en) 2003-10-24 2008-12-30 The University Of Miami Simplified tissue processing
US8288168B2 (en) 2003-10-24 2012-10-16 The University Of Miami Simplified tissue processing
US20090298172A1 (en) * 2008-05-28 2009-12-03 Steven Paul Wheeler Histological specimen treatment apparatus and method
US9366605B2 (en) 2008-05-28 2016-06-14 Steven Paul Wheeler Histological specimen treatment apparatus and method
WO2012003827A3 (en) * 2009-12-16 2012-08-02 Dako Denmark A/S Non-modal interplate microwave heating system and method of heating
CN102804913A (en) * 2009-12-16 2012-11-28 丹麦达科有限公司 Non-modal interplate microwave heating system and method of heating
US10281482B2 (en) 2009-12-16 2019-05-07 Dako Denmark A/S Non-modal interplate microwave heating system and method of heating
US10365189B2 (en) 2015-05-07 2019-07-30 Steven Wheeler Histological specimen treatment
US10641688B2 (en) 2015-05-07 2020-05-05 Steven Wheeler Histological specimen treatment
US11885723B2 (en) 2015-05-07 2024-01-30 Steven Wheeler Histological specimen treatment

Similar Documents

Publication Publication Date Title
US5289140A (en) Consistent diagnostic test method using microwaves
Falkendal et al. Massive galaxies on the road to quenching: ALMA observations of powerful high redshift radio galaxies
DE68914182D1 (en) Method and device for accelerated treatment of a thin sample on a surface.
Hintenlang Synergistic effects of ionizing radiation and 60 Hz magnetic fields
NZ502821A (en) Method and apparatus for generating analyte basis sets for use in spectroscopic analysis
WO2003087827A3 (en) Multi-parameter assays including analysis discs and methods relating thereto
Grundler et al. Resonant cellular effects of low intensity microwaves
US3449571A (en) Method of detecting and identifying microorganisms and other biologic materials
Leszczynski et al. Five years later: The current status of the use of proteomics and transcriptomics in EMF research
Katoh Microwave-assisted tissue preparation for rapid fixation, decalcification, antigen retrieval, cryosectioning, and immunostaining
Kobayashi et al. Microbeam irradiation facilities for radiobiology in Japan and China
US3956695A (en) Microwave spectral identification of cells
Yoshida et al. Apoptosis and proliferative activity in thyroid tumors
Tanimoto et al. Evaluation of antibodies reactive with porcine lymphocytes and lymphoma cells in formalin-fixed, paraffin-embedded, antigen-retrieved tissue sections
NO20002412L (en) Method of treating tumors and tumor cells using ex vivo activated T cells
Kriger et al. Applications of direct atomic laser spectral analysis of laser plasma for determination of inorganic component presence in biological objects
Marani Microwave applications in neuromorphology and neurochemistry: safety precautions and techniques
Ambrosone et al. High-Energy Neutrinos from Starburst galaxies: implications for neutrino astronomy
Szafran Age differences in choice reaction time and cardio-vascular status among pilots
US20100272629A1 (en) Method and system for providing a substance with receptive and/or transmissive properties for a signal
Moorlag et al. Microwave methods for reducing staining time to seconds
Bond et al. Microwave processing of gustatory tissues for immunohistochemistry
Moguilnaya et al. Using coherent spectroscopy for diagnosing cancer at its early stages
JP6421369B2 (en) Rapid and sensitive multiple immunostaining
Medina et al. Microwave irradiation improvements in the silver staining of the nucleolar organizer (Ag-NOR) technique

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAKO JAPAN CO LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:JORGENSEN, FINN;VABOE, BENT BORS;REEL/FRAME:005813/0764

Effective date: 19910812

STCF Information on status: patent grant

Free format text: PATENTED CASE

REMI Maintenance fee reminder mailed
FPAY Fee payment

Year of fee payment: 4

SULP Surcharge for late payment
AS Assignment

Owner name: DAKO CORPORATION, CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DAKO JAPAN CO., LTD.;REEL/FRAME:009015/0692

Effective date: 19980223

REMI Maintenance fee reminder mailed
FPAY Fee payment

Year of fee payment: 8

SULP Surcharge for late payment

Year of fee payment: 7

FEPP Fee payment procedure

Free format text: PAT HOLDER NO LONGER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: STOL); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

REFU Refund

Free format text: REFUND - 11.5 YR SURCHARGE- LATE PMT W/IN 6 MO, SMALL ENTITY (ORIGINAL EVENT CODE: R2556); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: REFUND - PAYMENT OF MAINTENANCE FEE, 12TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: R2553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

REMI Maintenance fee reminder mailed
FPAY Fee payment

Year of fee payment: 12

SULP Surcharge for late payment

Year of fee payment: 11

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY